Collecting and conveying mechanism



May 31, 1966 J. JONAKIN COLLECTING AND CONVEYING MECHANISM Filed May 8,1963 ATTORNEY United States Patent 3,253,777 COLLECTING AND CONVEYINGMECHANISM James Jonakin, Simsbury, Conn., assignor to CombustionEngineering, Inc., Windsor, Conn., a corporation of Delaware Filed May8, 1963, Ser. No. 278,880

2 Claims. (Cl. 233-46) This invention relates to collecting and conveyormechanism and particularly to mechanism for collecting partiallydewatered coal discharged from a centrifuge and conveying the dischargedcoal to a point of use such as a pulverizing mill or cyclone furnace.

In a system for handling a liquid-solid slurry and particularly in asystem for handling a pumpable slurry of crushed coal and water whereinit is desired to provide a continuous and regulated supply ofmechanically dewatered solids, it is necessary that the variouscomponents of the system including the mechanical dewatering device beable to operate continuously, performing its desired functions withoutinterruption over relatively long periods of time. With a slurry such asthe pumpable coal slurry which may originally have had a waterconcentration of 50% and where the mechanical dewatering reduces thisconcentration to approximately 20%, special precautions must be takenwith regard to the handling of the thus concentrated slurry, which is apasty material similar to a thick mud, so that a steady flow ismaintained and that plugging or stoppage is not encountered. The presentinvention is directed to a method and system employing a centrifugedewatering device of particular construction for the handling anddewatering of a liquid-solid slurry (such as a pumpable coal slurry) andwith the method and organization being such as to provide more sustainedoperation over long periods.

An object of the present invention is a method and mechanism forcollecting the pasty discharge from a centrifuge and conveying it at auniform rate to a point of use.

Other and additional objects will .be apparent from the followingspecification and claims and the attached drawings in which:

FIG. 1 is a side view partly in section showing the invention applied toa centrifuge and a bowl mill pulverizer; and

FIG. 2 is an end view partly in section of the mechanism of FIG. 1 withthe bowl mill removed.

In the coal firing of furnaces it is highly desirable to have acontinuous and uniform supply of coal to the furnace in order to providea steady and efficient combustion of the coal in the furnace. One of theproblems in collecting and transporting dewatered coal slurry from thecentrifuge to the furnace'has been the tendency of the dewatered coal,because of its pasty nature, to collect irregularly in the collector andchute directing the discharged coal slurry to the point of use such as apulverizing mill or a cyclone furnace. After some build-up the collectedor adhering slurry might let go irregularly and discharge a slug of coalat one time to provide too much coal at that time for eificientcombustion and during the build-up period supply insufficient coal forefiicient combustion. It is an object of applicants'invention toovercome this problem.

In the handling of pipeline coal and the supplying of this coal to afurnace for burning therein, as for example the furnace of a vaporgenerator, the coal slurry as it is conveyed through the long pipe lineis of a consistency which renders it desirable to remove a portion ofthe water prior to introducing the slurry into a firing system of afurnace. This concentration of the coal slurry to provide a coal slurryconcentrate of partially dewatered coal icg may be effected by means ofacentrifuge dewatering device, and the concentrate egressing from thecentrifuge may be conveyed to a furnace, such as a cyclone furnace, forburning therein or to a pulverizing mill and thence to a furnace. Forthe details with relation to such systems for the handling and burningof coal thus transported through a pipe line, including the uniform andcontinuous supply of slurry to a centrifuge, reference may be made toUS. application Serial No. 159,600, filed December 15, 1961, by JamesJonakin and Robert C. Tulis for Drying and Burning of Pipeline Coal, US.application Serial No. 159,603, filed December 15, 1961, by JamesJ'onakin for Method and Apparatus for Handling and Burning Fuel, andU.S. application Serial No. 215,203, filed August 6, 1962, now PatentNo. 3,211,369, issued Oct. 12, 1965, by Harry B. Jones and Donald J.Frey for Method and Apparatus for Handling Pipeline Coal.

In the embodiment illustrated to explain the present invention acentrifuge having a rotating drum 10, similar to that shown in the abovecited applications, is fed wit-h a continuous stream of pipeline slurryand discharges dewatered slurry through the discharge orifices 12 in acontinuous and uniform stream from each orifice. The bowl 10 which mayrotate at 1000 or 2000 r.p.m. imparts a centrifugal force to theconcentrate which provides the radial outward component to thetangentially discharged concentrate. A collector 14 surrounds thedischarge openings 12 and provides a stationary surface in the path ofthe discharged coal and against which the discharged coal impinges.'Ihis collector has a semi-circular portion 16 concentric with the axisof rotation of the bowl 10 and two tangential extensions 18 and 20inclined downwardly and away from said axis and forming a convergingchute having an open end 22 providing an opening through which coal maybe discharged into the pulverizer 24 and its bowl 26. The collector hasside plates 28 and 30 forming enclosures for the axially extendingsurfaces 32 of the collector. The collector thus provides an enclosurehaving one end formed of a semicircular shape with a linear axiallyextending surface and a converging chute extending from the open side ofthe semi-circle and having linear axially extending surfaces andterminating in an open discharge end. This collector may be supportedinany suitable manner, such as by bolts (not shown) from the centrifugehousing 34 a flange 36 is secured to the open end of the collector 14and serves as a means for fastening the collector to the pulverizer mill24 in a position to deliver the discharge from the collector to thepulverizer bowl 26. A pair of spaced chains 38 and 40 are threaded oversprockets 42 and 44 driven by a motor 46. Scraper blades 48 have one endsecured to a link in chain 38 and the other end secured to acorresponding link in chain 40 and extend outwardly from the chain andalong the linear axially extending surface of the collector 14 in anaxially extending direction. The chains 38 and 40 which act as holdersfor the scraper blades 48 are supported on and guided .by sprockets 50so as to position the scraper blades 48 adjacent the interior surface ofthe collector 14 including both the semi-circular and the tangentialchute portions. As the chains are driven in unison by the sprocket 42and 44 secured in fixed relation on the driven shaft 52 they will carrythe scraper blades 48 along the interior surface of the collector 14.The scraper blades 48 traveling over and along the interior surface ofthe collector 14 will dislodge any material that may tend to stick tothe surface of the collector and either push it along in front of thescraper blades or cause the material to drop or fall down onto a lowersurface of the collector such as the tangential portion 18 forming thelower surface of the discharge chute. The spaced scraper blades 48 serveto divide the the mill to the furnace.

concentrate collected on the interior surfaces of .the collector 14 intocomparatively small pockets orsegments which are pushed along thesurface 18 of the discharge chute and delivered in a uniform andcontinuous stream through the open end 22 of the discharge chute andinto the rotating pulverizer bowl 26. Each individual scraper bladepresents such a small surface to the concentrate and in operation isvibrated sufliciently so that there is little or no tendency for theconcentrate to build up on the individual blades. If desired, somecombustion air can be introduced near the lower end of the surface 18adjacent the point where the scraper blade leaves the surface for thebeginning of its return trip along the surface 20 to prevent anycollection of concentrate in this area. After delivery into thepulverizing mill 26 the coal will be pulverized by the usual pulverizingroll and transported in the usual manner by a stream of air passingthrough The concentrate in being discharged from the centrifuge forms anoutwardly radiating disc of discharging concentrate which is interceptedby the collector and confined within the collector chamber and istransported to the open discharge end of the collector chamber by theaxially extending scraper blades 48 mounted on the endless conveyor 38and 40 rotating around the axis of the discharge disc and the bowl 10.Thus an irregular accumulation of concentrate in the collector 14 isprevented and the concentrate is delivered in a continuous and uniformstream to the point of discharge which in the illustrated embodiment isa pulverizer mill.

While I have illustrated and described a preferred embodiment of myinvention, it is to be understood that such is merely illustrative andnot restricted and that variations and modifications may be made thereinwithout departing from the spirit and scope of the invention. Itherefore do not wish to be limited to the precise details set forth butdesire to avail myself'of such changes as fall within the purview of myinvention as defined in the following claims.

I claim:

1. In combination with a rotating centrifuge member having dischargeoutlets and rotating about a horizontal axis and separating liquid froma pumpable coal slurry and substantially continuously centrifugallydischarging partially dewatered coal as a pasty mass radially outwardfrom said discharge outlets in said rotating centrifuge member, astationary collector in the form of a semicircle,

concentric with said axis, wit-h extending portions, at

least one of which is tangential, forming a downwardly extendingconverging chute at the ends of said semicircle,

said collector surrounding said outlets and having an axially extendingcollector surface in the path of said mass as discharged, side platesforming, with said surface and centrifuge a substantially closedenclosure enclosing said discharge outlets and forming .a dischargeopening for said enclosure at the end of said extensions and side platesremote from said semicircle, an endless chain conveyor extending alongthe inner surface of said collector, a plurality of scrapers mounted onand spaced along, said chain. conveyor, means guiding said conveyor andscrapers along the inner surface of said collector with said scrapersclosely adjacent substantially the entire length of the inner surface ofsaid semicircle and extending portions, said scrapers located betweensaid discharge outlets of said centrifuge and said collector surface anddividing the pasty mass as discharged from said centrifuge and collectedon said collector surface into a plurality of segments along saidcollector surface and continuously pushing said segments along saidchute away from said axis and through said discharge opening, sprocketmeans for driving said conveyor and scrapers.

2. In combination with rotating mechanism rotating about a horizontalaxis and centrifugally delivering a substantially uniform, continuousstream of pasty material radially outward from and completely around theaxis of rotation of said mechanism, a stationary collector having acollecting surface around said axis in the path of said stream, saidsurface having a substantially semicircular portion with said axis asits center and having tangential extensions extending downwardly awayfrom said axis and forming a chute terminating in an open discharge end,said portion and extensions having an axially extending surface, atravelling scraper extending in an axial direction across said surface,an endless chain conveyor holding said scraper, a plurality of rotarysprockets including drive sprocket means supporting and directing saidscraper in a path adjacent said collecting surface including saidextensions, said scraper continuously removing material collected on andadhering to said surface and conveyingsaid material away from said axisalong one of said extensions to said open discharge end.

References Cited by the Examiner UNITED STATES PATENTS 775,320 11/1904Van Kirk 2337 1,195,000 8/1916 Labrador 210-372 2,104,162 1/1938Macklind 233-47 X 2,600,372 6/1952 Milliken et al. 2337 2,685,369 8/1954Crossley. 2,704,704 3/1955 Ogorzaly 302-66 X MARTIN P. SCHWADRON, ActingPrimary Examiner,

T. KLINKSIEK, Examiner

1. IN A COMBINATION WITH A ROTATING CENTRIFUGE MEMBER HAVING DISCHARGEOUTLETS AND ROTATING ABOUT A HORIZONTAL AXIAL AND SEPARATING LIQUID FROMA PUMPABLE COAL SLURRY AND SUBSTANTIALLY CONTINUOUSLY CENTRIFUGALLYDISCHARGING PARTIALLY DEWATERED COAL AS A PASTY MASS RADIALLY OUTWARDFROM SAID DISCHARGE OUTLETS IN SAID ROTATING CENTRIGUGE MEMBER, ASTATIONARY COLLECTOR IN THE FORM OF A SEMICIRCLE, CONCENTRIC WITH SAIDAXIS, WITH EXTENDING PORTIONS, AT LEAST ONE OF WHICH IS TANGENTIAL,FORMING A DOWNWARDLY EXTENDING CONVERGING CHUTE AT THE ENDS OF SAIDSEMICIRCLE, SAID COLLECTOR SURROUNDING SAID OUTLETS AND HAVING ANAXIALLY EXTENDING COLLECTOR SURFACE IN THE PATH OF SAID MASS ASDISCHARGED, SIDE PLATES FORMING, WITH SAID SURFACE AND CENTRIFUGE ASUBSTANTIALLY CLOSED ENCLOSURE ENCLOSING SAID DISCHARGE OUTLETS ANDFORMING A DISCHARGE OPENING FOR SAID ENCLOSURE AT THE END OF SAIDEXTENSIONS AND SIDE PLATES REMOTE FROM SAID SEMICIRCLE, AN ENDLESS CHAINCONVEYOR EXTENDING ALONG THE INNER SURFACE OF SAID COLLECTOR,